Snowball Earth: the Sturtian
Ice reaches the equator and stays for 56 million years — the longest glaciation in Earth's history.
- When
- —
- Duration
- 57 million years
- Known to
- ± 5 million years
- Era
- Neoproterozoic, Proterozoic
From 717 to 660 million years ago, glaciers extend to sea level at tropical latitudes and the oceans may have frozen over almost entirely. Recent work finds the Sturtian was not one continuous freeze but repeated snowball–hothouse cycles. Life survived, probably in open water near volcanic vents and in melt pools on the ice. Carbon dioxide accumulated from volcanoes for tens of millions of years until the greenhouse finally overwhelmed the ice.